Relationship of Geometry and Wavelength is Fundamental to the Vision Process

The finding of a direct relationship between geometry and light wavelength on the retinal surface may be the most fundamental insight of this work. It is seen that the exact center, i.e., ~550 nanometers, is geometrically defined at a retinal eccentricity of approximately seven degrees. This degree of retinal angle then becomes a fixed wavelength reference from which all other wavelengths can be compared in the vision process synthesizing  the hues of color. Edwin Land brilliantly deduced the presence of just such a reference in his comment “…we have learned that the eye must have a fantastic mechanism for finding a balance point within a band of wavelengths”. It seems clear that the presence of such a fixed reference provides an answer to the longstanding conundrum of the unique “color constancy” of vision – again, as Land proposed. We all “see green” because we all have the same sizes of retinal receptors and thus the same geometrically determined color reference!

The eye is then not to be viewed as a kind of  laboratory spectrometer that selects colors from different classes of cones but rather as a result of  evolutionary biology  where the fundamental physical principles of the diffraction of light and geometry are directly related to produce vision!

The following is an historic figure from Pirenne ⁽¹⁾ of a drawing made of this reference point on the retina. Note that this is the first point where octagonal symmetry is present. This is the eccentricity where sufficient rods have been introduced to completely surround each cone and a symmetrical structure results. On either side (i.e., inwards towards the fovea and outwards towards the peripheral retina) rods and cones are statistically distributed that has caused such confusion in the vision field attempting to find some order.

⁽¹⁾ I wish that that readers would review this seminal reference: “VISION AND THE EYE”, M.H. Pirenne, The Pilot Press Ltd., London, 1948

A NOTE REGARDING THE ABOVE FIGURE – I would assert that the figure represents, in the living state, a perfect octagonal symmetry since the ratio of the diameter of cones to rods is an exact ratio (1.8:1) to support that morphology. The microscopic sections that Pirenne must have used to create these drawings (and in the freeze-dried sections used in contemporary electron micrography) had been dried unavoidably introducing spatial distortion. GCH

This line of thought relating geometry and light wavelength leads directly to the processes involved in the evolution of the eye. It is obvious that the eye is the direct geometric materialization of the fundamental physics principles of the diffraction of light. If anyone wants to introduce “design” into this they will have to go back one step further into designing the  fundamental laws of physics!

And further, if one doubts that the basis for this explanation that chromatic aberration of the lens of the eye provides the information used in the vision process,  I will quote again from George Wald’s  “Blue-Blindedness” paper written in 1967 about which I commented  yesterday.

“Any lens made of one material exhibits chromatic aberration; it refracts short wavelength light more strongly than long wavelength light, and hence brings blue light to a shorter focus than red. Color-corrected lenses can of course be made by using two glasses differing in refractive index; but, so far as is known, no animal has yet succeeded in developing a color-corrected lens. Though the cheapest of cameras have color-corrected lenses, the lens system of the human eye – as Newton observed – has no color correction whatever”

Corroborated by this statement, and in the light of my geometric explanation, it is obvious that the eye uses chromatic dispersion (my term) to form the visual image (in the Fourier  frequency domain). This has heretofore been incorrectly, with unfortunate consequences, termed an aberration in the history of vision science!

Issac Newton saw this! Why has it been disregarded in vision science?

GCH

5/31/08